Problem: $J$ $K$ $L$ If: $ JL = 49$, $ JK = 4x + 2$, and $ KL = 2x + 5$, Find $KL$.
Solution: From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {4x + 2} + {2x + 5} = {49}$ Combine like terms: $ 6x + 7 = {49}$ Subtract $7$ from both sides: $ 6x = 42$ Divide both sides by $6$ to find $x$ $ x = 7$ Substitute $7$ for $x$ in the expression that was given for $KL$ $ KL = 2({7}) + 5$ Simplify: $ {KL = 14 + 5}$ Simplify to find ${KL}$ : $ {KL = 19}$